Endometrial cancer is the leading gynecological malignancy in industrialized countries. The World Health Organization classification categorizes endometrial hyperplasia as simple hyperplasia, complex hyperplasia without atypia, simple atypical, or complex atypical hyperplasia on the basis of architectural crowding and nuclear atypia. The severity of an endometrial hyperplasia reflects the risk of developing endometrial carcinoma. According to Kurman et al. (The behavior of endometrial hyperplasia. A long-term study of “untreated” hyperplasia in 170 patients. Cancer 56: 403-412), the risk of progression to carcinoma was less than 1% in simple hyperplasia. However, there are exceptions in patients with simple hyperplasia or complex hyperplasia without atypia in whom the progression to endometrial cancer occurred in a short period of time.
MicroRNAs (miRNAs) are evolutionarily conserved, non-coding RNA molecules that are usually 21-25 nucleotides in length, which function by binding to the 3′-untranslated regions (3′-UTRs) of mRNAs, where they repress protein translation or promote mRNA degradation (See Griffiths-Jones S (2004). The microRNA Registry. Nucleic acids research 32: D109-111). Most current studies of miRNAs are at a basic level and further work is needed to establish their clinical applications in endometrial cancer.
Cancer biomarkers for endometrial cancers, such as CA-125, have limited clinical application due to the low sensitivity and specificity of these biomarkers. Consequently, a non-invasive and convenient diagnostic method for predicting the risk of endometrial cancer and/or diagnosing endometrial cancer is needed and the present invention satisfy this and other needs.